FTCD4323E2PCL LR4 QSFP-DD transceiver modules are designed for use in 400 Gigabit Ethernet links on up to 10km of single mode fiber. They are compliant with the QSFP-DD MSA, QSFP28 MSA, 400G-LR4-10 Technical Specification Rev1.0 Sept 15, 2020 and portions of P802.3bs. Digital diagnostic functions are available via the I2C interface, as specified by the QSFP28 MSA and Finisar Application Note AN-21xx. The optical transceiver is RoHS compliant as described in Application Note AN-2038.